Hard calcified intrasellar schwannoma mimicking pituitary adenoma: a case report and review of the literature

Ectopic schwannoma of the sellar region in a 1-year-old child: A case report and review of literature

Background:

Schwannomas are cranial and spinal nerves’ sheath tumors accounting for up to 8% of all intracranial neoplasms. Although typical intracranial schwannomas originate from Schwann cells surrounding cranial nerves, ectopic schwannomas are not associated with a known cranial nerve or have an unknown origin. The location of schwannomas may impose clinical challenges. Sellar region schwannomas are rare whether it is ectopic or not. Herein, we report a pediatric case of a 1-year-old female with ectopic, intra-supra sellar with a literature review. We report the first case of juvenile ectopic schwannoma in the sellar region.

Methods:

A PubMed Medline database search was performed by the following combined formula of medical subject headings (MESH) terms and keywords: ((sella turcica [MeSH Terms]) OR (sella*[Title/Abstract]) OR (ectopic [Title/Abstract]) AND ((neurilemmoma [MeSH Terms]) OR (schwannoma [Title/Abstract]) OR (neuroma [Title/Abstract]) OR (neurinoma [Title/Abstract])).

Results:

Total results of 206 articles were obtained. In exclusion of intraparenchymal and intraventricular schwannomas, only 34 articles remained. Thirty-nine cases were included in 34 articles. According to the reported cases, intrasellar schwannomas are more common in elderly individuals in an average of 49.5 years (range: 19– 79 years). They have a good prognosis and affect males to females equally (20:19).

Conclusion:

Ectopic schwannoma sited in the sellar region is rare. It is the first case to be reported in the pediatric age group with a literature review. This lesion should be highlighted and included in the differential diagnosis of sellar mass.

[The 2017 WHO classification of pituitary tumors]

The 2017 WHO classification of pituitary tumors is still based on structural analyses and expression of various pituitary hormones. Three innovations have to be considered: (1) The expression of pituitary transcription factors Pit‑1, T‑Pit and SF‑1. (2) The term "atypical adenoma" was replaced by "aggressive adenoma". (3) The three tumor types of the neurohypophysis (pituicytoma, spindle cell oncocytoma, granular cell tumor) are defined by their common expression of TTF‑1. Craniophyryngiomas are identified as adamantinomatous type by focal nuclear expression of β‑catenin or as papillary type by demonstration of BRAF V600E mutation. Further primary tumors of the pituitary are extremely rare. These and also the other tumors of the sellar region can be structurally very similar to pituitary adenomas but can be-nearly without exception-differentiated by immunocytochemistry.

Primary intrasellar schwannoma with intratumoral hemorrhage mimicking pituitary apoplexy: A case report

Tumours growing in the sella turcica are mostly pituitary adenomas. We describe a rare case of primary intrasellar schwannoma with intratumoral bleeding. A 38-year-old man presented with headache in association with bilateral supratemporal quadrantopsia. MRI showed an intrasellar mixed signal mass lesion with suprasellar extension. The majority of the pituitary hormones were normal. He was diagnosed as non-functional pituitary adenoma with pituitary apoplexy. Subtotal resection was achieved eventually via an endoscopic transnasal trans-sphenoidal approach. The histopathologic diagnosis was schwannoma. It is the first intrasellar schwannoma with intratumoral hemorrhage in literature to date. It implied that the primary intrasellar schwannoma has potential risk of intratumoral bleeding, which should be considered in the differential diagnoses of sellar lesions.

Magnetic resonance imaging of the hypothalamo-pituitary region

The diagnosis and management of mass lesions in the sellar and parasellar areas remain challenging. When approaching patients with possible sellar or hypothalamic masses, it is important not only to focus on imaging but also detect possible pituitary hormone deficits or excess, in order to establish an appropriate diagnosis and initiate treatment. The imaging modalities used to characterize hypothalamic and pituitary lesions have significantly evolved over the course of the past several years. Computed tomography (CT) and CT angiography play a major role in detecting various sellar lesions, especially in patients who have contraindications to magnetic resonance imaging (MRI) and can also yield important information for surgical planning. However, MRI has become the gold standard for the detection and characterization of hypothalamic and pituitary tumors, infections, cystic, or vascular lesions. Indeed, the imaging characteristics of hypothalamic and sellar lesions can help narrow down the differential diagnosis preoperatively. In addition, MRI can help establish the relationship of mass lesions to surrounding structures. A pituitary MRI examination should be obtained if there is concern for mass effect (including visual loss, ophthalmoplegia, headache) or if there is clinical suspicion and laboratory evidence of either hypopituitarism or pituitary hormone excess. The information obtained from MRI images also provides us with assistance in planning surgery. Using intraoperative MRI can be very helpful in assessing the adequacy of tumor resection. In addition, MRI images yield reliable data that allow for noninvasive monitoring of patients postoperatively.

Very Unusual Sellar/Suprasellar Region Masses: A Review

The cause of sellar region masses in large retrospective series is overwhelmingly pituitary adenomas (84.6%), followed by craniopharyngiomas (3.2%), cystic nonneoplastic lesions (2.8%), inflammatory lesions (1.1%), meningiomas (0.94%), metastases (0.6%), and chordomas (0.5%) (1). While other rare lesions were also identified (collectively 6.0%), single unusual entities in the above-cited series numbered <1-2 examples each out of the 4122 cases, underscoring their rarity. We searched our joint files for rare, often singular, sellar/suprasellar masses that we had encountered over the past several decades in our own specialty, tertiary care specialty pituitary center practices. Cases for this review were subjectively selected for their challenging clinical and/or histological features as well as teaching value based on the senior authors' (MBSL, BKD) collective experience with over 7000 examples. We excluded entities deemed to be already well-appreciated by neuropathologists such as mixed adenoma-gangliocytoma, posterior pituitary tumors, metastases, and hypophysitis. We identified examples that, in our judgment, were sufficiently unusual enough to warrant further reporting. Herein, we present 3 diffuse large cell B cell pituitary lymphomas confined to the sellar region with first presentation at that site, 2 sarcomas primary to sella in nonirradiated patients, and 1 case each of granulomatosis with polyangiitis and neurosarcoidosis with first presentations as a sellar/suprasellar mass. Other cases included 1 of chronic lymphocytic leukemia within a gonadotroph adenoma and 1 of ectopic nerve fascicles embedded within a somatotroph adenoma, neither of which impacted patient care. Our objective was to share these examples and review the relevant literature.

Schwannoma in Sellar Region Mimics Invasive Pituitary Macroadenoma: Literature Review With One Case Report

In central nervous system, schwannomas, as ubiquitous tumors, mostly originate from sensory nerves like auditory and trigeminal nerves. However, intrasellar schwannomas are extremely rare. They are often misdiagnosed as pituitary adenomas. We report a rare case of schwannoma in the sellar region--a challenging diagnosis guided by clinical presentations, radiological signs, and postoperative pathological test. We represent a 65-year-old woman who had suffered from headaches, hypothyroidism, and visual disturbance. Her MRI revealed an abnormal sellar region mixed-signal mass lesion with suprasellar, left parasellar, and sellar floor invasiveness. We present detailed analysis of the patient's disease course and review relevant literatures. Written informed consent was obtained from the patient for publication of this article. A copy of the written consent is available for review by the editors of MEDICINE. Because this article does not involve any human or animal trials, there is no need to conduct special ethic review and the ethical approval is not necessary. When surgically treated, her specimen revealed a typical histopathology pattern of schwannoma. The patient's symptoms improved a lot after surgery and he continues to be under observation. Despite its rarity, intrasellar schwannoma should be considered in the differential diagnosis of sellar lesions that mimic pituitary adenomas.